embody something worth a hearing. Success is most likely to come by
considering the growth of alchemy; by trying to find the ideas which
were expressed in the strange tongue; by endeavouring to look at our
surroundings as the alchemists looked at theirs.

Do what we will, we always, more or less, construct our own universe.
The history of science may be described as the history of the
attempts, and the failures, of men "to see things as they are."
"Nothing is harder," said the Latin poet Lucretius, "than to separate
manifest facts from doubtful, what straightway the mind adds on of
itself."

Observations of the changes which are constantly happening in the sky,
and on the earth, must have prompted men long ago to ask whether there
are any limits to the changes of things around them. And this question
must have become more urgent as working in metals, making colours and
dyes, preparing new kinds of food and drink, producing substances with
smells and tastes unlike those of familiar objects, and other pursuits
like these, made men acquainted with transformations which seemed to
penetrate to the very foundations of things.

Can one thing be changed into any other thing; or, are there classes
of things within each of which change is possible, while the passage
from one class to another is not possible? Are all the varied
substances seen, tasted, handled, smelt, composed of a limited number
of essentially different things; or, is each fundamentally different
from every other substance? Such questions as these must have pressed
for answers long ago.

Some of the Greek philosophers who lived four or five hundred years